Remove Occurrences of Character from String

Given a string str and a character X, write a function to remove all occurrences of X from the string.

If the character X does not exist in the input string, the string should remain unchanged.

Example:

Input:

str = 'hello world'
X = 'o'

Output:

'hell wrld'

Constraints:

• 0 <= N <= 10^6, where N is the length of the string.
• Time Limit: 1 second